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From: David Miller <davem@davemloft.net>
Subject: Re: [RFC] [PATCH] Optimize TCP sendmsg in favour of fast devices?
Date: Thu, 21 Jan 2010 01:25:20 -0800 (PST)
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From: Krishna Kumar2 <krkumar2@in.ibm.com>
Date: Wed, 20 Jan 2010 17:49:18 +0530

> I had to remove the F_SG flag from cxgb3 driver (using ethtool
> didn't show any difference in performance since GSO was enabled
> on the device due to register_netdev setting it). Testing show a
> drop of 25% in performance with this patch for non-SG device,
> the extra alloc/memcpy is showing up.
> 
> For the SG driver, I get a good performace gain (not anywhere
> close to 25% though). What do you suggest?

I don't think we can add your change if it hurts non-SG
devices that much.